Electrically-controlled hoist.



S. H. LlBBY.

ELECTRICALLY CONTROLLED HOIST.

APPLICATION FILED MAY i. 1914.

Patemm'i 3mm 12, 3/937.

2 SHEETSSHEET l 1mm; rwtm Sam M. migh- EQMRE UHY, A COLsPUYEtATIQIli-015 Application filed May 1, 1914. Serial its.

aZZ whom it may concern Be it known l, SAM H. LIBBY, a citi-- Zen oi theUnited States, residing at East provision of improved means wherebycertain loading and conveying operations may be performed a reliable andetlicient manner with a minimum amount of apparatus.

My invention relates more specifically to hoisting mechanism oi the typeknown as grab bucket hoists, although my invention is not necessarilylimited to this specific type of apparatus. In the construction of grabbucket hoists, two winding drums are necessary, one for closing orlacing the bucket and the other for holding the bucket while the opening(and under some circumstances the closing) operation is going on; Here"tofore where these grab bucket hoists were operated electrically twomotors have been generally required, one for operating each drum. One ofthe objects of my invention is to provide means whereby the two drumsmay be operated by a single motor and controller to perform all thenecessary operations connected with the use of a grab bucket hoistwithout the use of manually operated clutching brakcs. In one specificembodiment of my invention the lacing drum is geared to the motor so asto be positively driven whenever the motor operates. The holding drum isdriven by the motor through electromagnetic friction clutch mechanismunder the control of the operator. The arrangement is such that thepower transmitted through the friction clutch will depend upon whetheror not the electromagnetic mechanism is energized. Under one condition,say for instance when the mechanism is energized, a light frictionclutch will be on, whereby a small amount of power will be transmittedto the holding drumenough to keep the cables taut, but when themechanism is denergizcd a heavy friction clutch will be on which willtransmit to the holding drum all the power received from the motor. Afriction brake is also applied. to the holding drum so that the bucketwill not overhaul the drum dur- Specification of Letters Patent.

fatented ing the opening or closing in air operations. Since the lacingdrum is operated for every movement of the hoist, and the ho] drum isonly operated during he sting and lowering, the single mom arranged asdo scribed performs all the nor ry tunetions. Other objects and purposesof my invention will appear in the course of the following specificationin which l have shown my invention embodied in concrete form forpurposes of 'llustration.

In the accomp anying crawing showing one embodii ent of myinvention,igureli an outline view in elevation of grab bucket hoist;Fig. 2 is a sectional view through the gear casing and the frictionclutch and brake mechanism; l 3 is a sectional view on line 3+3 of Fig.2; and Fig. is a diagram of the circuit connections.

Ref rring first to Fig. 1, it-will be seen that I have shown an ordinarygrab bucket hoist consisting of a conveyor housing; 10 carried by twotrucks l1 and 12 mounted upon the track 13 and getting power foroperating the same from two trolley wires, only one of which, 14, andone trolley 15 is shown. drums, that is, the lacing drum 16 and theholding drum 1?. The lacing drum has a single cable 18 which runsdownward to the grab bucket 19 and closes the bucket as the cable, onbeing drawn upward, turns the power wheel 19 in a clockwise directionand allows it to open, as the cable is lowered The holding drum has twocables, 20, 21, which are attached to the cross arm or upper centercasting 22 on the grab bucket. Thesecables 20 and 21 support the bucketwhile certain operations are taking place as hereinafter described, andcooperate with the cable 18 to lift the bucket.

Referring now to Fig. 2, the pinion 23 is for driving the lacing drum16, and the pinion it drives the holding drum 17. These pinions aregeared to their respective drums as shown in Fig. The motor shaft 25 islocated between these two gears. The gear case 26 forms a bearing forthe shafts upon which the gears 23 and are mounted and also for themotor shaft 25. The motor shaft drives the lacing drum directly andpositively through the gears 26, 27 and .23, so that the lacing drum isalways operated whenever the motor is operated. 'lhe hold- This conveyorcarries the two ing drum however, is not positively geared to the motor,but driven from the motor shaft through a friction clutch. This isaccomplished through a. sleeve 28 carrying a pinion 9,9 which mesheswith the gear 30 which in turn drives the pinion 2i and drum 1?. Thissleeve is driven from the motor shaft through a friction clutch mochanisai consisting of friction disks lil on the mot r shaftand frictionrings 32 carried by the sleeve. 'lhcse friction surfaces are pix-sod,together either by light or heavy spr ng presscrs depending upon whetheror not the electromagnet P18 is energized. 1n the specific arrangementshown when the magnet energized the light spring pres sure is appliedthrough spring 84: so that the sleeve is only lightly clutched to themotor shaft, but when the magnet is del nergizcd the heavy pressure isapplied by springs in addition to the light pressure and the sleeve isclutched strongly to the motor shaft. lhe sleeve .28 is elongated, andthe shaft 253 which extends through the sleeve has bearings 28 at eachend thereof. The end of the sleeve is formed into a flange 2-36 whichcooperates with the friction disks 3i splined to a hub 31 on the motorshaft and the friction rings 1-32. The friction rings are strung uponbolts 37 passing through the flange 36 so that they may move toward andaway from the flange but must turn with it. A. plate 38 also mountedupon the bolts 37 receives at its center the pressure of spring 3i whichproduces the light driving friction The spring 34': is made adjustableby means of the plug l. Another plate having a central opening forpermitting the spring M to pass through it, is pressed against the plate38 by springs 35. This plate 4.0 acts as the armature for theelectromagnet 3 the arrangement being such that when the magnet isenergized, the plate --'l-U will be attracted and. compress the springs35. thereby relieving the friction surface of the pressure of sprin 35.ll hen the magnet is det nergized, the friction surfaces are pressedtogether by all the springs. The spring -E-t presses against "the plate258, and the springs 35 press against the plate ita through the plate-l-U.

ihe net result is that when the magnet- 33 is dei nergized the frictionsurfaces-are pressed strongly together so as to clutch the sleevetightly to the motor shaft. llnder this condition the clutch willtransmit to the sleeve and hence to the holding drum all "the powerreceived from the motor. lint when the magnet is energized the frictionsurfaces are pressed together less strongly so that the clutch will nottransmit all the power received from the motor, but will slip, therebygiving to the sleeve a certain turning tendency which keeps the rabieson the holding drum taut. A. friction brake consisting of the fri tiondisks 1,229,.eea

and rings pressed together by springs -11 is arranged to apply a braketo the slee e. This brake operates between the sleeve and the hub l) ofthe gear casing, and is similar to that just described. Magnet windings43 control this brake so that when the windings are energized the brakeis released and when the windings arc tit-energized the brake is appliedto the holding drum. it will be seen, therefore, that when the motoroperates, it drives the lacing drum positively through gearing, butwhether or not it will drive the holding drum will depend upon whetheror not the clutch magnet 33 is energized. The holding drum will bebraked or free, depending upon whether or not the brake magnet isenergized.

In Fig. l 1 have shown 'a diagrammatic view of the motor connected tothe drums and clutch mechanism and have also shown the circuitconnections for the motor clutch, magnetic brake, etc.

The circuit connections will be understood by following through thevarious steps as they occur in actual practice. Assume that the bucketis openv and resting on the pile, say of coal, to be loaded. The firstopera ing position of the controller (position a) energizes the brakemagnet so as to take the brake off th motor. In this position of thecontroller the clutch magnet 33 is also energized through wires l5 andslip rings 46 (Fig. 2), thereby taking off the heavy friction clutchbetween the motor shaft and holding drum. In the next position (b) thecircuit of the motor M is closed through the resistance sections R andseries field F. The motor will now operate the lacing drum to close thebucket in the usual manner, and the holding. drum will simply put atension on the holding cables 20 and 21 and keep them taut. In the nexttwo positions (0 and d) of the controller the resistance sections arecutout of the armature and series field circuit and the motor operatesat a greater speed to close the bucket. In the next movement of thecontroller (position a), the clutch magnet 33 is dei nergized by thecontact finger 47 passing off its segment. This throws on' the heavyfriction clutch, whereby the motor drives the holding drum, one sectionof the resistance R being in circuit with the motor. Both drums nowstart to operate and 'aise the bucket by the three cables 18 20 and 21,the latter two cables only being taut enough to keep them from fouling.In the next position the resistance R is cut out of the armature andseries field circuit and the motor comes up to full hoisting speed. Whenthe hoisting operation is accomplished the operator turns the controllerto position (it) in which all circuits are opened and the brake isapplied to hold the bucket in its upper position by the ie/energizing ofwinding 4x3. The hoist is "by the motor through the ieoirsg dr'e i.

iower the bucket,

iii desired bosition, t

-i i heii the bucket has opened and iris iooci is dumped the ogeretorturns the con-iroiier book no position (ii) and trowerses the hoist back"so Hie loading station, after which he turns oontroiier to posiizioiito in. abiiis position the some magnet is'rieenergiseii so that homing;drum Wiii operate with the motor as W811i as the drum aiici lower ifnebucket, i ie broke beiiig reiesseri. The motor is out o f I in thisposition and connected in a dynamic brake c i. h the resistance smi onec t-ion of the resist-once R. In the next position of the coiitroiierthe remainder of ie resists-rice ii is connected in circuit so "heoucket cie soends more rapidly. the position (m) of the controiier, thebrake is applied to the motor, sensing oo ois being oi? and theoontroiier iieiidie having made oompie'te revolution being now resciy toagain compieixe the cycire of operation. iiii some, cases, as, forinstance, Where there is 110%., room to Withdraw the open boeko from aspace which it hos entered, ihe bucket must first be 'cioseoi. Underthese circuiiistarises after the bucket has opened the coii'tiioiier isturned back to position in which the bucket is closed The bucket must srwermi be opener} and the operation continued as above ciesoribed. Itwill thus be seen with my arrangement s sin gie motor i sense to performoil the operations incl 5- iosding and imiooiding, hoissmg mic ing of egrab bucket or simiizuhOiSii, all operations being" performed by esingle coriiroiier sod xvii-bout the use foot brakes hand brakes ormeiioeiiy opereteri eiiiizciies. 'Wiiiie i have ciesorioool myioveoibi ias em bodied in ootooreie form onci operif io s syeciiic marinerpurposes iiii tie i it siiouid oe iiiriciersizoo that do not ETinversion f ere'zo, si" e arious riselvos to siiose skilled in from. thes airit; of my inversion. the em oe oi which is forth in the annexe-r1 c.s.

2 e to secure by Letters Patent of the Uniteri is,

A grab bucket hoist or *biieii re core- Esing i racing cirusio onelectric Thor hovriving connectionstherewith, i1oiiin drum and meanswhereby she motor op erases time hoiciiog cirum so as to suop bucketduring ioociiiig and lift ii hoisting,

9. A grab bucket hoist or ithe iiire prising eiecing oirum our; hoioiian eieofirio motor boring am positive our connection. with one of ssici(iiUIllS eiee, mognetiooiiv controlled. friction eiu mechanism betweenthe motor and o drum, and means whereby the frici' iieotioii transmitsmore or less power pending upon whether or 'not he eier-Lro magneticmechanism is ener iizedi ii. gmio bucket hoist or HR iiirnju m prisingo. isoing drimi are. eirr A moiur {5,1 iim 'ijog positive drivingcommotion there with, o. holding drum, and. an. electromagneticeii ycontrolled driving connection for transmitting more or less power fromike motor the holding ii-om His will oi the 1 operebor" A. grab oucietmost or the hire com" prising a iaci'ng drum, on iotor hei "mg adrivingconnection fisher uh, o

- prising drum, on eieeizric mo'iaor new will of the operator, and 2111ing a posii'l've driving conneoiion iii 2L ildiiillg drum, frictional(ii 611;; coon-ootiers "the motor o'oc'i the holding}; drum, andeieotromogneiio means controT. oi? 01 M01 for power or (:5, through.iiie .v RBCtiGl'l.

grab brisket iioisi; or ii prising so lacing drum, heviiig' coriioiciiiig (13711111 iiieeins amount of power WilBEfii" may from themotor $0 the 110101 ceiiy actuated broke on the no 8. A bucket hoist orprising 2i lacing drum, o o r .iiPoVilfigl s driving coneotioir o,iioiriing drum fission ciu all provided with iiiosiis for effecting thetransmission oi. meii amount of power between the i'noror i iii theholding drum at s1]. times and :i grea amount under the control of iheoperate and on eieotromogneiiioaiiy not-fiuoizeii .5 tion brake on theholding cirumi 9 A bucket hoist or 1 we prising a lacing drum, anelectric motor ha ing a positive driving connection therewith, a holdingdrum, elect-rtunagnetically controlled friction clutch mechanism hetweenthe holding drum and the motor. and means whereby the frictionconnection transmits more or less power depending upon whether or notthe electromagnetic mechanism is energized.

10. it grab bucket hoist or the like coniprising a lacing drum, anelectric motor having a positive driving connection therewith, a holdingdrum, electromagnetieally controlled friction clutch mechanism betweenthe holding drum and the motor, and means whereby the frictionconnection transmits more power when the electromagnetic mechanism isdeenergized than when it is energized.

1.1. A. grab bucket hoist or the like comprising a lacing drum, anelectric motor having its shaft connected to positively drive the. same,a holding drum, a sleeve on the motor shaft geared to the holding drum,

magnetic clutch mechanism connecting the motor shaft and the sleeve soas to transmit a greater or less amount of power from the motor to theholding drum at the will of the operator, and an electromagneticallycontrolled friction brake upon the sleeve for braking the holding drum.

12. A grab bucket hoist or the like coniprising a lacing drum, anelectric motor having a driving connection therewith, a hold ing drum, afriction clutch connecting the holding drum and the motor shaft, meansfor exerting a small ainount of pressure 'at all times on the frictionclutch, and electrz magnetically controlled means for exerting a greaterpressure on the friction clutch at the will of the operator.

Inwitness whereof, I have hereunto set my hand this twenty ninth day ofApril,

' SAM H. LIBBY.

Witnesses:

ROGER H. BUTTERWORTH, FREDERICK KEYLER.

